#subject ⇒ void

subject was contributed by Joe Ferris to support the one-liner
syntax embraced by shoulda matchers:

describeWidgetdoit{is_expected.tovalidate_presence_of(:name)}# or
it{shouldvalidate_presence_of(:name)}end

While the examples below demonstrate how to use subject
explicitly in examples, we recommend that you define a method with
an intention revealing name instead.

Note:

Because subject is designed to create state that is reset
between each example, and before(:context) is designed to setup
state that is shared across all examples in an example group,
subject is not intended to be used in a before(:context) hook.